The meteoritic origin of Tutankhamun's iron dagger blade          下载免费PDF全文

Daniela Comelli  Massimo D'orazio  Luigi Folco  Mahmud El‐Halwagy  Tommaso Frizzi  Roberto Alberti  Valentina Capogrosso  Abdelrazek Elnaggar  Hala Hassan  Austin Nevin  Franco Porcelli  Mohamed G. Rashed  Gianluca Valentini 《Meteoritics & planetary science》2016,51(7):1301-1309

Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis. Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x‐ray fluorescence spectrometry, strongly supports its meteoritic origin. In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun's dagger blade, in comparison with other simple‐shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun's time.  相似文献   

Rayleigh waves in magneto-thermo-microelastic half-space under initial stress     

A. M. Elnaggar  A. M. Abd-Alla 《Earth, Moon, and Planets》1989,45(2):175-185

The aim of the present paper is to investigate the influence both of intitial stress and magnetic field on the propagation of Rayleigh waves in thermo-microelastic half-space subjected to certain boundary conditions. The wave velocity equation has been obtained. If the initial stress and the electromagnetic field are ignored, the frequency equation as obtained by Locket (1958).  相似文献   

On the dynamical problem of a generalized thermoelastic granular infinite cylinder under initial stress     

A. M. Elnaggar 《Astrophysics and Space Science》1992,190(2):177-190

The object of the present paper is to investigate the influence of initial stress on the waves propagation in a generalized thermoelastic granular medium subjected to the boundary conditions that the outer surface is traction free. In addition, it is subjected to temperature boundary conditions. The wave velocity equation for the generalized thermoelastic granular medium Rayleigh wave under the influence of initial stress has been obtained. The classical result has been derived as a limiting case similar to one which was obtained by Ewinget al. (1957).  相似文献   

Readily dispersible clay and its role in the mobility of transition metals Cd2+, Cu2+ and Zn2+ in an alkaline alluvial soil     

Mohamed Rashad  Essam Elnaggar  Faiz F. Assaad 《Environmental Earth Sciences》2014,71(9):3855-3864

Readily dispersible clay is the part of the clay fraction in soils that potentially disperses in water when a small amount of mechanical energy is applied to soil. Column and batch experiments were conducted to identify the effect of readily dispersible clay on the mobility of some metal ions in a disturbed soil sample. The clay fraction (<0.002 mm) was separated from an alkaline Vertisol from the Nile River Delta. X-ray diffraction technique was used to identify minerals present in the clay fraction. Clay suspensions and deionized H₂O solutions of Cd²⁺, Cu²⁺, and Zn²⁺ were prepared and used as influents in soil columns. Adsorption capability of the studied soil among the three metal ions was investigated. The results showed high adsorption capacity of Cd²⁺, Cu²⁺, but not Zn²⁺ for the studied soil. Cu²⁺ was the highest adsorbed metal by soil and its sorption increased at small equilibrium concentrations compared with Cd²⁺ and Zn²⁺. For the three studied metal ions, Langmuir model represented the best fit to the adsorption data. The concentration of Zn²⁺ and Cd²⁺ in leachates increased as the leaching solution volume increased, while Cu²⁺ showed a homogeneous distribution throughout the soil column. According to DTPA extractable metals, Zn²⁺ was appeared at greater depths than Cd²⁺, while Cu²⁺ had homogeneous distribution through the soil column.  相似文献   

Prediction of future situation of land use/cover change and modeling sensitivity to pollution in Edku Lake,Egypt based on geospatial analyses     

Abd El-Hamid  Hazem T.  El-Alfy  Muhammad A.  Elnaggar  Abdelhamid A. 《GeoJournal》2021,86(4):1895-1913

GeoJournal - Assessing land use/cover (LULC) change in coastal lakes is an essential process for sustainable development. Edku Lake is one of the most important lakes in the northern part of Nile...  相似文献